Mercury(II) chlorideormercuric chloride(archaically,corrosive sublimate) is thechemical compoundofmercuryand chlorinewith theformulaHgCl2.
Mercuric chloride is not a salt but a linear triatomic molecule, hence its tendency to sublime.In the crystal, each mercury atom is bonded to two close chlorideligandswith Hg—Cl distance of 2.38 Å; four more chlorides are more distant at 3.38 Å.
Mercuric chloride is obtained by the action ofchlorine
on mercury ormercury(I) chloride, by the addition ofhydrochloric acidto a hot, concentrated solution of mercury(I) compounds such as the nitrate
HgNO3+ 2 HCl ? HgCl2+ H2O + NO2,
Heating a mixture of solid mercury(II) sulphateandsodium chloridealso affords volatile HgCl2, whichsublimesand condenses in the form of small rhombic crystals.
The main application of mercuric chloride is as a catalystfor the conversion ofacetylenetovinyl chloride, the precursor topolyvinylchloride
C2H2+ HCl ? CH2=CHCl
For this application, the mercuric chloride is supported on carbon in concentrations of about 5 weight percent. This technology has been eclipsed by the thermal cracking of1,2-dichloroethane. Other significant applications of mercuric chloride include its use as adepolarizerin batteries and as a reagent inorganic synthesisandanalytical chemistry(see below).It is being used in plant tissue culture for surface sterilisation of explants such as leaf or stem nodes.


Thanks
Ruchi
Askiitians Faculty